Drug residues in food animals II. Plasma and tissue kinetics of oxytetracycline in young cross-bred swine

Autor: Patricia E. Long, D. H. Showalter, Richard H. Teske, H. Dwight Mercer
Rok vydání: 1978
Předmět:
Zdroj: Journal of Veterinary Pharmacology and Therapeutics. 1:119-128
ISSN: 1365-2885
0140-7783
DOI: 10.1111/j.1365-2885.1978.tb00315.x
Popis: Tissue distribution and elimination kinetics of oxytetracycline in sixteen organs and body fluids were determined in young pigs following intravenous and oral administration. Seventeen non-fasted pigs, 8–10 weeks of age, weight range 16.4–34.5 kg were dosed intravenously at a dose rate of 11 mg/kg bodyweight. An additional seventeen weaning pigs, 12–14 weeks of age, weight range 27.2–36.3 kg were dosed orally at a dose rate of 48–65 mg/kg bodyweight. Oxytetracycline was rapidly distributed (half-life, 6.71 ± 1.13 min) in swine. The mean volume of distribution was 1.26 ± 0.18 l/kg and overall body clearance was 3.82 ± 0.59 ml/kg/min. The elimination half-life of oxytetracycline in pigs was 3.87 ± 0.62 h, which is shorter than has been observed in other domestic animal species. Oxytetracycline became rapidly and efficiently involved in enterohepatic cycling, with as much as 70% of a total intravenous dose being available for reabsorption from the gastrointestinal tract within 1 h after administration. This high degree of enterohepatic recycling prolonged the half-life, and the large amount of drug that entered the enteric tract contributed to the high volumes of distribution and high k12/k21 ratios. The excellent tissue penetration of this drug further contributed to the high volume of distribution and high k12/k21 ratios obtained. Relationships between plasma and tissue depletion for several major edible organs were found to be statistically significant. Blood plasma is proposed as a body fluid for monitoring oxytetracycline tissue residues.
Databáze: OpenAIRE
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